My shy stepsister catches me masturbating and she wants me to fuck her really hard until she makes her cum. I on top of her.

My stepsister has caught me masturbating a couple of times, when I've done it in the living room, the kitchen, her room and in the bathroom, when she surprises me in my stepparents' room she looks so good that I masturbate and asks me to do the same from porn videos in real life, I tell her what she is like and I pour my milk in her belly.